baityoudaoicibaDictgodict[bait 词源字典]
bait: [13] Etymologically, the verb bait means ‘cause to bite’. It comes from Old Norse beita, a causative version of bita ‘bite’ (related to English bite). This took two semantic paths in English. In its aggressive mode, it meant literally ‘set dogs on someone’, and hence by figurative extension ‘harrass, persecute’. More peaceably, it signified ‘feed an animal’.

And this sense of ‘food provided’ is reflected in the noun bait, which comes partly from the verb, partly from the related Old Norse nouns beit ‘pasturage’ and beita ‘fish bait’. Old Norse beita was probably borrowed into Old French as beter, which with the prefix aproduced abeter, source of English abet [14], originally meaning ‘urge on, incite’.

=> abet, bite[bait etymology, bait origin, 英语词源]
bait (n.)youdaoicibaDictgodict
"food put on a hook or trap to lure prey," c. 1300, from Old Norse beita "food," related to Old Norse beit "pasture," Old English bat "food," literally "to cause to bite" (see bait (v.)). Figurative sense "anything used as a lure" is from c. 1400.
bait (v.1)youdaoicibaDictgodict
"to torment or goad (someone unable to escape, and to take pleasure in it)," c. 1300, beyten, a figurative use from the literal sense of "to set dogs on," from the medieval entertainment of setting dogs on some ferocious animal to bite and worry it (the literal use is attested from c. 1300); from Old Norse beita "to cause to bite," from Proto-Germanic *baitan (cognates: Old English bætan "to cause to bite," Old High German beizzen "to bait," Middle High German beiz "hunting," German beizen "to hawk, to cauterize, etch"), causative of *bitan (see bite (v.)); the causative word forked into the two meanings of "harass" and "food offered." Related: Baited; baiting.
bait (v.2)youdaoicibaDictgodict
"to put food on a hook or in a trap," c. 1300, probably from bait (n.). Related: Baited; baiting.